COSEE Pacific Partnerships PRIME Internship Program for Community College Students

Monday, July 15, 2013

Cris - Week 3

Charleston Boat Basin. Source: Google Maps

On Monday, July 8 I collected my first round of settlement plates. I collected a total of 24 plates, 12 from the inner boat basin and 12 from the outer. I have a total of eight moorings with four plates each, but I will only count the fouling organisms on six of the moorings. The remaining two moorings will be kept for the remainder of this project in order to compare the rate of fouling to the adult population of the inner and outer boat basin. To the right is a map of where my moorings are located. A red mark indicates a single mooring, and a green mark indicates two - one mooring that is checked weekly and one permanent one. The three moorings furthest out in the outer basin (the two marks furthest right in the picture) were weighted with lead because the current is much stronger there than at the other locations.

Upon examining the plates I realized that the subsampling method, with the 25 random squares, would not suffice because there was not enough settlement. Instead, I have to count every individual of interest; using a transparent overlay with printed rows to keep my place on the plate when counting under the microscope. The plate sits inside of a plexiglass case with a bezel on which the lined overlay sits. Organisms of interest include various species of ascidians (colonial and solitary), bryozoans, hydrozoans, sponges, barnacles, and the polychaete spirorbid worm.

Belanus glandula

By far the most settled group of organisms are the ascidians. The colonial ascidians Distaplia occidentalisand Botryllus schlosseriwere the most abundant and can even be seen by the naked eye on the plates. Barnacles were also found in very high numbers - on one plate I counted over 80- but they were mostly found in the outer basin (more specifically at the fifth site). I have yet to find any Didemnum vexillum on any of my plates, with the exception of the ones on the permanent moorings which have not been examined yet.

Striped Dolphin (Stenella coeruleoalba)

Apart from my work in the Emlet lab, I have also had the opportunity to recover the body of a striped dolphin (Stenella coeruleoalba) at Bullards Beach State Park in Bandon. It had washed up on the beach on Friday, July 12 and Dr. Jan Hodder was notified. She asked two fellow interns, two students, and myself to find and recover the animal. It was not yet mature and the reason for its being beached is unknown. Birds had begun to peck at its gut and its melon before we had arrived. The dolphin was frozen the same day to be stored until it is dissected later in the semester. Until next week, cheers!